将关联数组中的代码与硬编码值进行比较

我有一个文本文件，其中包含以下值，将用作用户名和密码

根=>用户
根=
>密码鼓励性=>月光
帮助我=>

validateUser.php文件中validateUser函数的代码

function validateUser($username, $password)
{
    $filename = 'userCreds.txt';
    $file = fopen($filename, "r");
    if($file==false)
    {
        echo"Error opening file";
        exit();
    }
    $i=0;
    static $Credentials = array();
    foreach (file($filename) as $line)
    {
        list($key,$value) = explode("=>",$line,2) + array(NULL,NULL);
        if($value !== NULL)
        {
            $Credentials[$key] = $value;
        }
    }
    print_r($Credentials);
    echo "<br>";
    //static $Credentials = array("root"=>"user","rtam"=>"password","q"=>"continuum");
    if(array_key_exists($username, $Credentials))
    {
        echo "$Credentials[$username] <br>"; 
        echo "$password <br>";
        if($Credentials[$username] == $password)
        {
            return TRUE;
        }
        else
        {
            echo $Credentials[$username]," is not equal to ",$password,"<br>";
            return FALSE;
        }
    }
    else return FALSE;
}

<?php
include_once "validateUser.php";
$username = "root";
$password = "user";
if(validateUser($username,$password))
{
    echo "<h2>Welcome! <br></h2>";
}
else 
{
    echo "Try again <br>";
}
?>

$username和password的值从一开始就硬编码，用于测试。

我遇到的问题是，当我从文本文件中比较用户名和密码并比较两者时，它们不匹配。

即使我打印出两个值，即$password和$Credentials[$username]，我在屏幕上得到相等的值，但if语句不能识别它使用if($Credentials[$username] == $password)

我做错了什么?